1. Field of the Invention
The present invention relates to a voltage to current converting circuit and, more particularly, to a voltage to current converting circuit capable of operation over a wide range with low distortion and low power requirements.
2. Description of the Prior Art
A typical voltage to current converting circuit uses a differential amplifier to convert a signal voltage e into a balanced signal current.
One such prior art circuit simply connects the ends of the signal source to the inputs of a differential amplifier and takes the current in one of the outputs of the amplifier as the signal current. This circuit is only useful for signal voltages having a maximum range of 10 mv. Signals with voltages having a greater range cause distortion of the output signal that is unacceptable for most applications.
One solution to that problem uses one or more current sources and resistors connected to the emitters of the differential amplifier transistors. The maximum range of the circuit is increased, but so is the power required for its operation.